A field reaserch that aimed to get the appropriate of N application and frequency of topping was conducted in the experimental field of Brawijaya University, located in Jatikerto village, Malang. The experimental treatments consist of four levels of N (0 ; 67.5 kg N ha-1, 135 kg N ha-1 and 202.5 kg N ha-1) and four levels frequency of topping (without topping, 1, 2, and 3 of topping). These treatments were arranged in a split plot design; N application in the main plot and frequency of topping in the subplot with three replications. Data was collected destructively including component of growth, component of yield and plant growth analysis. F test at 5% is used to determine the effect of treatments, while the average difference between treatments was referred to Duncan value at 5%. The result showed there were significantly interaction between N application and frequency of topping on component of growth and weight of tuber per plant. Combination of N application dosage 202.5 kg ha-1 and non or once topped had resulted the highest of leaf area and leaf area duration. While the highest of weight tuber per plant was obtained on N dosage 135 kg ha-1 and topping one times.